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https://www.readbyqxmd.com/read/28431161/engineering-a-high-affinity-peptide-binding-site-into-the-anti-cea-mab-m5a
#1
Cindy Zer, Kendra N Avery, Kassondra Meyer, Leah Goodstein, Krzysztof P Bzymek, Gagandeep Singh, John C Williams
We have previously identified a cyclic peptide called meditope which binds to the central cavity of the Fab portion of cetuximab and shown that this peptide binding site can be grafted, or 'meditope-enabled', onto trastuzumab. This peptide has been shown to act as a hitch for the non-covalent attachment of imaging agents to meditope-enabled antibodies. Herein, we explore the process of grafting this peptide binding site onto M5A, an anti-CEA antibody in clinical trials for cancer diagnostics. In order to explore the contributions of the amino acids, we sequentially introduced pairs of amino acid substitutions into the Fab and then we reverse-substituted key residues in the presence of the other substitutions...
April 19, 2017: Protein Engineering, Design & Selection: PEDS
https://www.readbyqxmd.com/read/28430443/theoretical-investigation-of-the-binding-of-nucleobases-to-cucurbiturils-by-dispersion-corrected-dft-approaches
#2
Natarajan Sathiyamoorthy Venkataramanan, Ambigapathy Suvitha
The encapsulation of nucleobases, inside CB7 has gained prominence due to its use as anticancer and antiviral drugs. With this respect, the nonconvalent interactions exists in the nucleobases encapsulated inside the CB7 cavity have been analyzed employing the dispersion corrected density functional theory. The CBn cavity has the ability to encapsulate two guest nucleobases molecules, when they are aligned in parallel configuration. The computed association energy using the two and three body correction method computed at B3LYP-D3 level is close to the experimental estimate...
April 21, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28430417/charge-separation-mechanisms-in-ordered-films-of-self-assembled-donor-acceptor-dyad-ribbons
#3
Jenna L Logsdon, Patrick E Hartnett, Jordan N Nelson, Michelle A Harris, Tobin J Marks, Michael R Wasielewski
Orthogonal attachment of polar and nonpolar side-chains to a zinc porphyrin-perylenediimide dyad (ZnP-PDI, 1a) is shown to result in self-assembly of ordered supramolecular ribbons in which the ZnP and PDI molecules form segregated π-stacked columns. Following photoexcitation of the ordered ribbons, ZnP(+•)-PDI(-•) radical ion pairs form in <200 fs and subsequently produce a 30 ± 3% yield of free charge carriers that live for about 100 μs. Elongating the side chains on ZnP and PDI in 1b enhances the order of the films, but does not result in an increase in free charge carrier yield...
April 21, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28430413/bioimaging-with-macromolecular-probes-incorporating-multiple-bodipy-fluorophores
#4
Ek Raj Thapaliya, Yang Zhang, Pravat Dhakal, Adrienne S Brown, James N Wilson, Kevin Collins, Françisco M Raymo
Seven macromolecular constructs incorporating multiple borondipyrromethene (BODIPY) fluorophores along a common poly(methacrylate) backbone with decyl and oligo(ethylene glycol) side chains were synthesized. The hydrophilic oligo(ethylene glycol) components impose solubility in aqueous environment on the overall assembly. The hydrophobic decyl chains insulate effectively the fluorophores from each other to prevent detrimental interchromophoric interactions and preserve their photophysical properties. As a result, the brightness of these multicomponent assemblies is approximately three times greater than that of a model BODIPY monomer...
April 21, 2017: Bioconjugate Chemistry
https://www.readbyqxmd.com/read/28430279/microcontact-printing-with-aminosilanes-creating-biomolecule-micro-and-nanoarrays-for-multiplexed-microfluidic-bioassays
#5
Shivani Sathish, Sébastien G Ricoult, Kazumi Toda-Peters, Amy Q Shen
Microfluidic systems integrated with protein and DNA micro- and nanoarrays have been the most sought-after technologies to satisfy the growing demand for high-throughput disease diagnostics. As the sensitivity of these systems relies on the bio-functionalities of the patterned recognition biomolecules, the primary concern has been to develop simple technologies that enable biomolecule immobilization within microfluidic devices whilst preserving bio-functionalities. To address this concern, we introduce a two-step patterning approach to create micro- and nanoarrays of biomolecules within microfluidic devices...
April 21, 2017: Analyst
https://www.readbyqxmd.com/read/28430197/g-quadruplex-organic-frameworks
#6
Yi-Lin Wu, Noah E Horwitz, Kan-Sheng Chen, Diego A Gomez-Gualdron, Norman S Luu, Lin Ma, Timothy C Wang, Mark C Hersam, Joseph T Hupp, Omar K Farha, Randall Q Snurr, Michael R Wasielewski
Two-dimensional covalent organic frameworks often π stack into crystalline solids that allow precise spatial positioning of molecular building blocks. Inspired by the hydrogen-bonded G-quadruplexes found frequently in guanine-rich DNA, here we show that this structural motif can be exploited to guide the self-assembly of naphthalene diimide and perylene diimide electron acceptors end-capped with two guanine electron donors into crystalline G-quadruplex-based organic frameworks, wherein the electron donors and acceptors form ordered, segregated π-stacked arrays...
May 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28430191/activating-lattice-oxygen-redox-reactions-in-metal-oxides-to-catalyse-oxygen-evolution
#7
Alexis Grimaud, Oscar Diaz-Morales, Binghong Han, Wesley T Hong, Yueh-Lin Lee, Livia Giordano, Kelsey A Stoerzinger, Marc T M Koper, Yang Shao-Horn
Understanding how materials that catalyse the oxygen evolution reaction (OER) function is essential for the development of efficient energy-storage technologies. The traditional understanding of the OER mechanism on metal oxides involves four concerted proton-electron transfer steps on metal-ion centres at their surface and product oxygen molecules derived from water. Here, using in situ (18)O isotope labelling mass spectrometry, we provide direct experimental evidence that the O2 generated during the OER on some highly active oxides can come from lattice oxygen...
May 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28429738/fatty-acid-synthase-cooperates-with-protrudin-to-facilitate-membrane-outgrowth-of-cellular-protrusions
#8
Chuanling Zhang, Jiaqi Lu, Huizhong Su, Jing Yang, Demin Zhou
Cellular protrusion formation capacity is a key feature of developing neurons and many eukaryotic cells. However, the mechanisms underlying membrane growth in protrusion formation are largely unclear. In this study, photo-reactive unnatural amino acid 3-(3-methyl-3H-diazirin-3-yl)-propamino-carbonyl-Nε-l-lysine was incorporated by a genetic code expansion strategy into protrudin, a protein localized in acidic endosomes and in the endoplasmic reticulum, that induces cellular protrusion and neurite formation...
April 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28429595/ultrasensitive-detection-of-micrornas-with-morpholino-functionalized-nanochannel-biosensor
#9
Tangbin Liao, Xiaorui Li, Qian Tong, Kai Zou, Hang Zhang, Lina Tang, Zhongyue Sun, Guo-Jun Zhang
Here we demonstrate a phosphorodiamidate morpholino oligos (PMO)-functionlized nanochannel biosensor for label-free detection of microRNAs (miRNAs) with ultrasensitivity and high sequence-specificity. PMO, as a capture probe, was covalently anchored on the nanochannel surface. Because of the neutral character and high sequence-specific affinity of PMO, hybridization efficiency between PMO and miRNAs was enhanced, thus decreasing background signals largely and improving the detection specificity and sensitivity highly...
April 21, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28429501/formation-of-macromolecules-in-wheat-gluten-starch-mixtures-during-twin-screw-extrusion-effect-of-different-additives
#10
Kaiqiang Wang, Cheng Li, Bingzhi Wang, Wen Yang, Shuizhong Luo, Yanyan Zhao, Shaotong Jiang, Dongdong Mu, Zhi Zheng
BACKGROUND: Wheat gluten comprises a good quality and inexpensive vegetable protein with an ideal amino acid composition. To expand the potential application of wheat gluten in the food industry, the effect of different additives on the physicochemical and structural properties of wheat gluten/starch mixtures during twin-screw extrusion was investigated. RESULTS: Macromolecules were observed to form in wheat gluten/starch mixtures during twin-screw extrusion, which may be ascribed to the formation of new disulfide bonds and non-covalent interactions, as well as Maillard reaction products...
April 21, 2017: Journal of the Science of Food and Agriculture
https://www.readbyqxmd.com/read/28429451/a-strong-cis-effect-in-an-imidazole-imidazolium-substituted-alkene
#11
Dayne C Georgiou, Mohammad A Haghighatbin, Conor F Hogan, Michael S Scholz, James N Bull, Evan J Bieske, David J D Wilson, Jason L Dutton
We report the first example of an alkene with two carbon-bound substituents (imidazole and imidazolium rings) where the Z-isomer has a greater thermodynamic stability than the E-isomer which persists in both the gas phase and in solution. Theoretical calculations, solution fluorescence spectroscopy and gas-phase ion mobility mass spectrometry studies confirm the preference for the Z-isomer, the stability of which is traced to a non-covalent interaction between the imidazole lone pair and the imidazolium ring...
April 21, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28428687/lysyl-oxidase-its-diversity-in-health-and-diseases
#12
REVIEW
Suchitra Kumari, Tarun Kumar Panda, Tapaswini Pradhan
The mechanical properties of extracellular matrix (ECM) and connective tissues is largely dependent on the collagen and elastin structure. Lysyl oxidase (LOX) plays a critical role in the formation and repair of the ECM by oxidizing lysine residues in elastin and collagen, thereby initiating the formation of covalent cross linkages which stabilize these fibrous proteins. Due to its multiple functions both extracellularly and intracellularly, lysyl oxidase is involved in several processes in the tumorigenic pathway, in many different cancer types and stages...
June 2017: Indian Journal of Clinical Biochemistry: IJCB
https://www.readbyqxmd.com/read/28428562/dehydroascorbic-acids-modified-polymer-micelles-target-cancer-cells-to-enhance-anti-tumor-efficacy-of-paclitaxel
#13
Xiaoyu Pei, Feifei Luo, Jun Zhang, Wulian Chen, Chen Jiang, Jie Liu
Paclitaxel (PTX), especially albumin-bound PTX in clinical, has displayed significant inhibition of tumor growth in patients. But the systemic distribution and poor water solubility of PTX often lead to severe side effects, consequently limiting the anti-tumor efficacy. In this study, we developed a novel PTX-loaded polymeric micelle drug delivery system. These self-assembled polymeric micelles from core to outside consisted of poly L-phenylalanine (pPhe), DTSSP linked poly L-lysine (pLys), poly ethylene glycol (PEG) and dehydroascorbic acids (DHA)...
April 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28428442/combination-of-ibrutinib-and-abt-199-in-diffuse-large-b-cell-lymphoma-and-follicular-lymphoma
#14
Hsu-Ping Kuo, Scott A Ezell, Karl J Schweighofer, Leo Wk Cheung, Sidney Hsieh, Mutiah Apatira, Mint Sirisawad, Karl Eckert, Ssucheng J Hsu, Chun-Te Chen, Darrin M Beaupre, Matthias Versele, Betty Y Chang
Diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) are the most prevalent B-lymphocyte neoplasms in which abnormal activation of the Bruton's tyrosine kinase (BTK)-mediated B-cell receptor (BCR) signaling pathway contributes to pathogenesis. Ibrutinib is an oral covalent BTK inhibitor that has shown some efficacy in both indications. To improve ibrutinib efficacy through combination therapy, we first investigated differential gene expression in parental and ibrutinib-resistant cell lines to better understand the mechanisms of resistance...
April 20, 2017: Molecular Cancer Therapeutics
https://www.readbyqxmd.com/read/28428366/in-vitro-metabolism-of-oprozomib-an-oral-proteasome-inhibitor-role-of-epoxide-hydrolases-and-cytochrome-p450s
#15
Zhican Wang, Ying Fang, Juli Teague, Hansen Wong, Christophe Morisseau, Bruce D Hammock, Dan A Rock, Zhengping Wang
Oprozomib is an oral proteasome inhibitor currently under investigation in patients with hematologic malignancies or solid tumors. Oprozomib elicits potent pharmacological actions by forming a covalent bond with the active site N-terminal threonine of the 20S proteasome. Oprozomib has a short half-life across preclinical species and in patients due to systemic clearance via metabolism. Potential for drug-drug interactions (DDIs) could alter the exposure of this potent therapeutic therefore a thorough investigation of pathways responsible for metabolism is required...
April 20, 2017: Drug Metabolism and Disposition: the Biological Fate of Chemicals
https://www.readbyqxmd.com/read/28428345/proliferation-of-primary-human-hepatocytes-and-prevention-of-hepatitis-b-virus-reinfection-efficiently-deplete-nuclear-cccdna-in-vivo
#16
Lena Allweiss, Tassilo Volz, Katja Giersch, Janine Kah, Giuseppina Raffa, Joerg Petersen, Ansgar W Lohse, Concetta Beninati, Teresa Pollicino, Stephan Urban, Marc Lütgehetmann, Maura Dandri
OBJECTIVE: The stability of the covalently closed circular DNA (cccDNA) in nuclei of non-dividing hepatocytes represents a key determinant of HBV persistence. Contrarily, studies with animal hepadnaviruses indicated that hepatocyte turnover can reduce cccDNA loads but knowledge on the proliferative capacity of HBV-infected primary human hepatocytes (PHHs) in vivo and the fate of cccDNA in dividing PHHs is still lacking. This study aimed to determine the impact of human hepatocyte division on cccDNA stability in vivo...
April 20, 2017: Gut
https://www.readbyqxmd.com/read/28428079/mineralization-inhibiting-effects-of-transglutaminase-crosslinked-polymeric-osteopontin
#17
Betty Hoac, Valentin Nelea, Wenge Jiang, Mari T Kaartinen, Marc D McKee
Osteopontin (OPN) belongs to the SIBLING family (Small, Integrin-Binding LIgand N-linked Glycoproteins) of mineral-binding matrix proteins found in bones and teeth. OPN is a well-known inhibitor of matrix mineralization, and enzymatic modification of OPN can affect this inhibitory function. In bone, OPN exists both as a monomer and as a high-molecular-weight polymer - the latter is formed by transglutaminase-mediated crosslinking of glutamine and lysine residues in OPN to create homotypic protein assemblies...
April 17, 2017: Bone
https://www.readbyqxmd.com/read/28428038/non-invasive-tracking-of-hydrogel-degradation-using-upconversion-nanoparticles
#18
Yuqing Dong, Guorui Jin, Changchun Ji, Rongyan He, Min Lin, Xin Zhao, Ang Li, Tian Jian Lu, Feng Xu
Tracking the distribution and degradation of hydrogels in vivo is important for various applications including tissue engineering and drug delivery. Among various imaging modalities, fluorescence imaging has attracted intensive attention due to their high sensitivity, low cost and easy operation. Particularly, upconversion nanoparticles (UCNPs) that emit visible lights upon near-infrared (NIR) light excitation as tracking probes are promising in deciphering the fate of hydrogels after transplantation. Herein, we reported a facile and non-invasive in vivo hydrogel tracking method using UCNPs, where the degradation of hydrogels was determined using the decrease in fluorescence intensity from the UCNPs encapsulated in the hydrogels...
April 17, 2017: Acta Biomaterialia
https://www.readbyqxmd.com/read/28427675/use-of-pva-%C3%AE-mno2-stearic-acid-nanocomposite-films-prepared-by-sonochemical-method-as-a-potential-sorbent-for-adsorption-of-cd-ii-ion-from-aqueous-solution
#19
Shadpour Mallakpour, Forough Motirasoul
Alpha manganese dioxide (α-MnO2) nanorods have been covalently functionalized with stearic acid by solvothermal method. The α-MnO2-stearic acid nanorods were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. The amount of stearic acid grafted onto α-MnO2 surface was determined about 41wt% by thermogravimetric analysis. The α-MnO2-stearic acid nanorods was used as nanofiller for the preparation of poly(vinyl alcohol) (PVA) nanocomposites (NCs)...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28426937/high-throughput-quantitative-intrinsic-thiol-reactivity-evaluation-using-a-fluorescence-based-competitive-endpoint-assay
#20
Tomoya Sameshima, Ikuo Miyahisa, Seiji Yamasaki, Mika Gotou, Toshitake Kobayashi, Junichi Sakamoto
In a high-throughput screening (HTS) process, the chemical reactivity of test samples should be carefully examined because such reactive compounds may lead to false-positive results and adverse effects in vivo. Among all natural amino acids, the thiol side chain in cysteine has the highest nucleophilicity; thus, assessment of intrinsic thiol group reactivity in the HTS processes is expected to accelerate drug discovery. In general, kchem (M(-1)s(-1)), the secondary reaction rate constant of a compound to thiol, can be evaluated via time course measurements of thiol-compound adducts using liquid chromatography-mass spectroscopy; this requires time-consuming and labor-intensive procedures...
April 1, 2017: SLAS Discovery
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